Method, system and apparatus for synergistically raising the potency of enhanced oil recovery applications

ABSTRACT

The invention provides an apparatus, method and system for stimulating production of a natural resource (e.g., Oil, gas or water) producing well using vibrational energy delivered to the geological formation combined with one or more existing EOR treatments. Pressure waves are applied through a device that maybe permanently installed, and continuously or periodically operated during EOR treatment and even later during recovery of the natural resource. The vibrational energy provide a synergistic effect with existing EOR treatments, enhancing the outcome of EOR treatments. The invention provides a downhole type apparatus constructed to resist corrosion and provides one or more heat sink chambers for controlling heat dissipation during operation. The system provided by the invention is capable of monitoring production, adapting stimulation parameters based on user input and other pertinent parameters.

FIELD OF THE INVENTION

The invention relates to recovering natural resources such as oil andnatural gas from a geological formation; particularly the inventionrelated to a method, apparatus and system for stimulating wells usingacoustic waves during a treatment of the well by one or more existingapplications for stimulating wells.

BACKGROUND OF THE INVENTION

There exist several extraction methods to improve productivity from oilwells. However in the upstream crude oil industry, 60% to 70% ofOriginal Oil In Place (OOIP) is typically left in the reservoir afterthe use of normal primary and secondary recovery techniques (Society ofPetroleum Engineers. www.spe.org). The benefits of improving extractionmethods are substantial. For example, there are thousands of oil wellsin Texas, USA, alone, which could benefit from improving oil productionoutput. If it were possible to recover even 50% of the heavy oildeposits, the US could supply 50% of North American demand for another50 to 75 years (Dr. Franklin Foster, 2006).

A well for extracting fluids from geological formations is constructedby drilling a hole from the surface toward the geological formation thatcontains a natural resource, and that has adequate permeability to letfluids produced in the formation flow toward the well. The well's wallsare lined with a cement layer and a casing that houses and supports aproduction tube string coaxially installed in its interior. In addition,perforations are made in the well lining in order to connect the wellwith the reservoir, supplying a path or trajectory inside the formation.Tubes provide an outlet for the fluids obtained from the formation.

Typically, there are numerous perforations that extend radially from thelined or coated well. Perforations are uniformly separated in thelining, and pass to the outside of the lining through the formation. Inan ideal case, perforations are only located within the formation, andtheir number depends on the formation thickness. It is rather common tohave nine, and up to twelve perforations per depth meter of formation.Other perforations extend longitudinally, and yet other perforations mayextend radially from a 0°-azimuth, while additional perforations,located every 90° may define four sets of perforations around azimuth.Formation fluids pass through these perforations and come into the lined(or coated) well.

Preferably, the oil well is plugged by a sealing mechanism, such as ashutter element, or with a bridge-type plug, located below the level ofperforations. This shutter element is connected to a production tube,and defines a compartment. The production fluid, coming from theformation or reservoir, enters the compartment and fills the compartmentuntil it reaches a fluid level. Accumulated oil, for example, flows fromthe formation and can be accompanied by variable quantities of naturalgas. Hence, the lined compartment may contain oil, some water, naturalgas, and solid particles, with normally, particles settling at thebottom of the compartment.

The fluid produced in the formation may change its phase when there is areduction of pressure around the well; this change of phase causes thegasification of the lightest molecules. Also, the oil well can producevery heavy molecules. Over time, due to several reasons, oil wellproductivity gradually diminishes. Two main causes of the reduction inproductivity are related to relative permeability: a decrease of thefluidity of crude oil, and the deposit of solids in the perforations.

Crude oil's fluidity diminishes over time and progressively obstructspores in a deposit or reservoir. On the other hand, solids such asclays, colloids, salts, paraffin etc. accumulate in perforation zones ofthe well. These solids reduce the absolute permeability, orinterconnection between pores. Problems associated with the causesmentioned above are: obstruction of pores by mineral particles that flowjointly with the fluid to be extracted, precipitation of inorganicscales, decanting of paraffins and asphalt or bitumen, hydration ofclay, invasion of solids from the mud and filtration of perforation mud,as well as invasion of termination fluids and solids from brineinjections. Each of the above mentioned causes can produce apermeability reduction, or a flow restriction in the zone surroundingoil well perforations. This defines the pore size connecting to thefluid inside formation, allowing the fluid flow from the formationthrough cracks or fissures, or connected pores, and finally the fluidcomes to interstitial spaces within the compartment and is collected.During that flow, very small solid particles from the formation, called“fines,” may flow; but instead they tend to settle.

After a certain time, trajectories through perforations extending insidethe formation of a reservoir may become obstructed with “fines” orresidues. While the “fines” can be kept in a disperse state for sometime, they can agglomerate and plug the pore space, reducing the fluidrate or production quantity. This may become a problem that is fed backto the well and cause a production decrease. More and more “fines” cankeep settling on perforations, plugging them more and more, even tendingto halt a minimum flow rate.

There exist several treatment methods to improve productivity from oilwells. Periodic stimulation of oil and gas wells is done by applyingthree general types of treatment: acid treatment, fracturing, anddefault treatment with solvents and heat. Acid treatment consists ofusing mixtures of acids HCl and HF (hydrochloric acid and hydrofluoricacid), which is injected in the production zone (rock). Acid is used fordissolving reactive components (carbonates, clay minerals, and in asmaller quantity, silicates) in the rock, thus increasing permeability.Frequently, additives are incorporated, such as reaction retardingagents and solvents, to improve acid performance in the acidizingoperation and/or protect the equipment from acid attacks.

While acid treatment is a common treatment to stimulate oil and gaswells, this treatment has multiple drawbacks among which that thepenetration depth of active (or live) acid is generally less than 5inches (12.7 cm) into the rock. Furthermore, the cost of acids and thecost of disposing of production wastes are high. Acids are oftenincompatible with the crude oil; and acid may produce viscous oilyresidues inside the well. Precipitates may also form once the acid isconsumed.

Hydraulic fracturing is another technique usually used for stimulatingoil and gas wells. In this process, high hydraulic pressures are used toproduce vertical fractures in the formation. Fractures can be filledwith polymer plugs, or treated with acid (in rocks, carbonates, and softrocks), to form permeability channels inside the wellbore region; thesechannels allow oil and gas to flow. However, the cost of hydraulicfracturing is extremely high (as much as 5 to 10 times higher than acidtreatment costs). In some cases, fracture may extend inside areas wherewater is present. The latter may lead to an increase of the quantity ofwater in the extracted oil, which significantly diminish theproductivity of oil.

Hydraulic fracture treatments extend several feet from the well, and areused more frequently when rocks are of low permeability. The possibilityof forming successful polymer plugs in all fractures is usually limited,and problems such as plugging of fractures and grinding of the plug mayseverely deteriorate productivity of hydraulic fractures.

Another method for improving oil production in wells involves injectingsteam. One of the most common problems in depleted oil wells isprecipitation of paraffin and asphaltenes or bitumen inside and aroundthe well. Steam has been injected in such wells to melt and dissolveparaffin into the oil or petroleum, and then all the mixture flows tothe surface. Frequently, organic solvents are used (such as xylene) toremove asphaltenes or bitumen whose melting point is high, and which areinsoluble in alkanes. Steam and solvents are very costly (solvents moreso than steam), particularly when marginal wells are treated, producingless than 10 oil barrels per day (1 bbl=159 liters). Furthermore, in theabsence of mechanical mixing, which is required for dissolving ormaintaining paraffin, asphaltenes or bitumen in suspension, theapplication of steam and solvents is less efficient than may beexpected.

Therefore, the a need for a method, apparatus and system for improvingwell productivity that enhance the potency of the existing enhanced oilrecovery applications, and potentially reduce the cost and/or time ofapplication of the existing technologies. The invention provides asystem, apparatus and method for use in combination with enhanced oilrecovery applications to increase production capacity of oil, gas andwater wells.

SUMMARY OF THE INVENTION

The invention provides a system, an apparatus and methods for increasingproductivity of a natural resource producing-well. The inventionprovides an apparatus that utilizes one or more elastic-waves generatorshosted inside a chamber. The chamber is made of (or protected by) acorrosion-resistant material, that allow the apparatus to be efficientlyused in harsh chemical environments.

The invention provide a highly efficient and versatile means to increasethe mobility of fluids within the well bore region of anoil/water/gas-well. The method and system may be adapted to the geologyof the reservoir. In one embodiment of the invention, the systemutilizes an acoustic device of the “downhole” type, that is, at thebottom of the well and/or the perforated zone of the well, to generatemechanical waves of an extremely high energy. Such high energy iscapable of removing deposits of fines, organics, scales and inorganicdeposits inside the well and in the wellbore region. A deviceimplementing the invention may have an insulated andcontrolled-environment chamber, for protection against mechanical wavesgenerated by the acoustic generators, and against corrosion byhydrocarbons present in the formation, and from high temperature. Thelater configuration allows for the installation of several types ofsensors and devices to acquire data from the well bottom, wellboreand/or the perforated zone.

One or more embodiments of the invention deliver an acoustic device foroil, gas, and water well, which does not require injection of chemicalsfor their stimulation.

The invention provides an acoustical device for stimulating wells in theperforation zone (downhole) that can operate inside a tube withoutneeding the withdrawal or elimination said tube. Alternatively, thedevice may be coupled to the tube using an adapter, in order to operatewhile being during production.

The regime of operation in accordance with the invention may be adaptedto the type of well (e.g., Oil, Gas or any combination of both), to typegeology and all other aspects of factors that limit the production in awell. The method and system embodying the invention are highly versatileand may be adapted for use specifically to treat any of a plurality ofconditions. Embodiments of the invention may comprise an acoustic devicecapable of being used in one or more different types of reservoirs,crude type, gas content, and combined environments. The acoustic devicemay operate with an corrosion-resistant heatsink chamber that emitsand/or radiates power as elastic waves directed to the formation, andthat likewise avoids the contact of hydrocarbons and other fluids withthe radiator and other inner components of the system preventingcorrosive damage.

Another embodiment of the invention provides a corrosion-resistantheatsink chamber that acts as an acoustic resonance chamber. Theinvention takes into account the disposition of the wave generator andprovides a plurality of geometries that are adequate to address aplurality of conditions. The corrosion-resistant heatsink chamber alsoprevents the system from overheating, by means of a heatsink liquidwhich fills the device, allowing the system to work in gas reservoirs oroil wells with high concentration of gas. When working in heavy oilwells, the capacity to efficiently transfer the heat generated by thewave radiators to the environment, also improves the capacity of thesystem to reduce the viscosity of the crude oil, for example, thusfacilitating the crude oil flow and extraction.

Furthermore, an embodiment of the invention provides a device thatallows the connection of one or more acoustic devices in a single well,thus allowing an installation that fulfills the specific requirementsfor each well.

The invention provides a device for generating elastic waves that areapplied to a geologic formation simultaneously with the applications ofone or more enhanced oil recovery (EOR) treatment methods. The inventionprovides numerous alternatives to applying EOR methods alone, becausethe outcome of almost every existing EOR technique may be improved whenused in combination with the acoustic wave application. The applicationof high-frequency elastic waves, low-frequency elastic waves or acombination thereof may stimulate the formation while applying anexisting EOR method, which results in an increase of the efficiency ofthe treatment.

For example, while treating a formation with acid, the high-frequencyvibration may increase the efficacy of the acid to dissolve sediments(e.g., carbonate scales and the like), while the low-frequencyvibrations may open the cracks in the formation, thus allowing theacidic solution to travel deeper into the rock, react with and dissolvethe debris that clog the orifices and allow the opening of more pores(deeper) into the rock. Similar applications may be contemplated usingthe combination of the apparatus, method and system of the inventionwith one or more existing EOR techniques, such as fracturing, heat andsolvent treatments, and any other available treatment method.

In the extreme case of “depleted” oil wells, the combination disclosedby the invention of applying elastic waves while treating a well with anexisting EOR technique, may result in the reactivation of the well. Awell may be categorized as “depleted” based on the cost effectiveness ofproduction from the well, rather than the amount of resource stillpresent in the formation. The formation may still contains oil reserves,for example, when the flow to a specific well decreases to a point wherethe amount of oil recovered from that well does not justify the cost ofproduction. In the latter case the well is considered “depleted”, andmay be eventually abandoned. When a depleted well is treated inaccordance with an embodiment of the invention, i.e., using acombination of elastic wave application with an existing EOR technology,the well may be reactivated and sufficient amounts of oil may becomeavailable for recovery to justify restarting production.

Elastic waves application may be combined, in accordance withembodiments of the invention, with steam/water injection. The elasticwaves may be applied as high-frequency, low frequency or a combinationof high- and low-frequency elastic waves while steam/water is beingapplied according to existing methods of treating wells withsteam/water. The combination, as thought by the invention, increases themobility of injected fluids, increase the mobility of reservoir fluidsleading to an increase of productivity. The application of elastic wavesin combination with the application of steam/water treatment, inaccordance with the invention, allows for cleaning of the injectionpores/channels, and an increase of the limit of the flow of water.

The invention teaches a method and system for combining the applicationof elastic waves along with chemical treatment of the well. Theapplication of elastic waves to a well allows for deeper chemicalpenetration into the formation, an increased reactivity of the chemicalcompounds with the substrates (e.g., rocks material, sediment deposits,mineralization byproducts), increased mobility of the chemical solutionsthrough the formation, and an alteration of the oil-to-water interface.

The invention teaches combining elastic waves application in combinationwith hydraulic fracturing treatments. The pressure waves created by theapplication of elastic waves may travel to varying distances from thewell, depending on the frequency of the elastic wave. The effects ofapplying elastic waves to a well in combination with fracturingtreatments, in accordance with embodiments of the invention, lead to along-lasting treatment effect, an increase of oil mobility through newfractures, increased mobility of proppant particles through cracks inorder to keep openings wider and, hence, lasting long for fluid flow.

Moreover, a system embodying the invention provides a plurality ofsensors, data collection, data transmission and data processing modules,that may all be used during a treatment according to any EOR techniquewhen combined with the deployment the elastic waves generating deviceprovided by the invention. The benefits of the latter modules includeoptimization of the time required to treat each specific well and theadjustment of the treatment parameters in real-time (e.g., the acidsolution composition in the case of the acidizing EOR, or the pressureof water in the case of hydraulic fracturing or any other parametersassociated with the any other EOR).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that represents components of a systemutilized to increase well production in accordance with one embodimentof the invention.

FIG. 2A shows a schematic representation of a typical well forextracting oil and/or gas, aiming at presenting the context in which anembodiment of the invention is utilized.

FIG. 2B shows a schematic representation of a typical well forextracting oil and/or gas undergoing a dual treatment with elastic wavesand one or more EOR treatments in accordance with an embodiment of theinvention.

FIG. 3 is a block diagram representing components of a well stimulationdevice in accordance with embodiments of the invention.

FIG. 4 represents a longitudinal section view through a device forstimulating wells in accordance with an embodiment of the invention.

FIG. 5 is a block diagram representing components of a high-powergenerator for powering one or more magnetostrictive transducers inaccordance with one embodiment of the invention.

FIG. 6A and FIG. 6B show a cross section view and a perspective sectionview, respectively, of a submersible cable as used in one embodiment ofthe invention.

FIG. 7A is a flowchart diagram of method steps involved in fabricatingelastic waves generator using magnetostrictive material in accordancewith an embodiment of the invention.

FIG. 7B is a plot of the temperature for curing resin versus time ofcuring in accordance with embodiments of the invention.

FIG. 8 shows a set of plots that represent vibrational energy transferalong the longitudinal and radial axes between a device implementing theinvention and the surrounding area in the operation zone.

FIG. 9 illustrates the geometry of a device implementing the inventionwhere the layout of transducers in relation with wave propagationproperties is used to optimize the amount of vibration energytransferred to the surrounding operation zone.

FIG. 10 illustrates the interaction between the transducer and the wallof the chamber when geometry is adequately configured to utilize theresonance properties of the device implementing the invention.

FIG. 11A illustrates examples of geometries for the layout of aplurality of acoustic wave sources hosted within one or more devicesimplementing the invention.

FIG. 11B illustrates geometries of various dispositions of an acousticwave source with regard to the wall of the chamber in accordance withone or more embodiments of the invention.

FIG. 12A and FIG. 12B represent a longitudinal and transversal sectionviews, respectively, of a device implementing the invention where one ormore acoustic waves generators are in direct contact with the wall ofthe radiating chamber.

FIG. 13 shows a longitudinal section view of a device implementing theinvention where the diameter of the device exceeds that of the tubing ina well, and the means to attach the device to the tubing.

FIG. 14 a longitudinal section view illustrating several layers thatallow a tubing in accordance with an embodiment of the invention toenhance the heat transfer rate to the crude in the reservoir in order toreduce viscosity of crude oil.

FIG. 15 is a flowchart diagram representing the overall steps comprisedin deploying a system embodying the invention, applying one or morepreliminary treatment, and permanently operating the system.

FIG. 16 is a flowchart diagram showing steps involved in deploying adevice implementing the invention.

FIG. 17 is a flowchart diagram representing steps of cleaning a wellbefore permanent operation in accordance with one embodiment of theinvention.

FIG. 18 is a flowchart diagram representing steps comprised in theprocess of cleaning a well in accordance with an embodiment of theinvention.

FIG. 19 is a flowchart diagram representing steps comprised in heattreatment of heavy oil in accordance with one embodiment of theinvention.

FIG. 20 is a flowchart diagram representing steps comprised in thepermanent installation of a system embodying the invention.

FIG. 21A is a plot of the power as a function of time of a highfrequency continuous signal for driving a wave generator, in accordancewith one embodiment of the invention.

FIG. 21B is a plot of the power as a function of time of a highfrequency signal for driving a wave generator, where the signal isapplied in an ON/OFF fashion, in accordance with one embodiment of theinvention.

FIG. 21C is a graph showing the power level as a function of time of ahigh-frequency signal that is applied in a pulsed mode, in accordancewith an embodiment of the invention.

FIG. 21D is a bode diagram showing the magnitude of the signal and thephase of the signal as a function of frequencies of signals propagatedthrough a geological formation in accordance with applications of theinvention.

FIG. 21E is a plot of a low frequency wave 2175 resulting from theapplication of a burst of high-frequency signal.

FIG. 22A is a plot of a modulated high frequency signal used to applylow-frequency acoustic vibrations in accordance with an embodiment ofthe invention.

FIG. 22B shows a plot of a signal having a low-frequency that resultsfrom the application of the signal shown in FIG. 22A.

FIG. 23 is a plot representing a signal whose frequency is modulated inaccordance with an embodiment of the invention.

FIG. 24 is flowchart diagram showing the overall steps provided by animplementation of the invention for applying a combination of elasticwaves stimulation and another EOR treatment.

FIG. 25 is a flowchart diagram representing steps involved in atreatment of a well using a combination of hydraulic fracturing andelastic wave treatment in accordance with an embodiment of theinvention.

FIG. 26 is a flowchart diagram showing steps involved in gas injectionin combination with elastic waves stimulation in accordance with anembodiment of the invention.

FIG. 27 is a flowchart diagram representing steps involved in acidizinga well in combination with the application of elastic waves to a wellbore in accordance with embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides an apparatus, method and system for increasingproduction capacity of oil, gas and water wells utilizing a versatiledevice that is adaptable to various applications. The invention alsoprovides methods and a system to use the device in various exploitationreservoirs that have various geologies.

In the following description, numerous specific details are set forth toprovide a more thorough description of the invention. It will beapparent, however, to one skilled in the pertinent art, that theinvention may be practiced without these specific details. In otherinstances, well known features have not been described in detail so asnot to obscure the invention. The claims following this description arewhat define the metes and bounds of the invention.

Terminology

The following detailed description is frequently concerned with oilwells; the invention however is intended to be adapted for other typesof wells to extracting other types of natural resources such as naturalgas and water from geological formations.

In the following description, a reference to an enhanced oil recovery(EOR) treatment encompasses any available technology that may be used tostimulate production in a newly built well and/or a well for whichstimulation is sought to increase production. A few exampleimplementations are described in details in the following disclosure.However, one with ordinary skills in the art of oil well stimulationwould recognize that numerous variations of the invention may bepracticed without departing from the scope and the spirit of theinvention.

In the following, a reference to a user may refers to a person, amachine (e.g., a computer) acting on behalf of a person, and in otherinstances a person may refer to a group of persons or a company.

Description of the General Concept

FIG. 1 is a block diagram that represents components of a systemutilized to increase well production in accordance with one embodimentof the invention. A system embodying the invention comprises a waveradiator 120. The wave radiator is a device capable of deliveringvibrational power 125 to a geological formation 150 such as an oil orgas containing reservoir. In embodiments of the invention, the waveradiator 120 is capable of delivering power in a wide range of power andfrequency, the level of which is determined by a user (e.g., an oil/gasfield manager) and/or a control system 110.

In embodiments of the invention, the wave radiator may deliver acousticwaves, mechanical waves, electromagnetic waves or any type of physicalphenomenon capable of delivering vibrational energy to a geologicalformation.

The system embodying the invention comprises a sub-system 130 forcollecting data 136 from the operating area, including the geologicalformation. The data collection/monitoring system 130 comprises one ormore sensors for collecting a plurality of environmental data. Forexample, the sensors may collect temperature, pressure, viscosity,conductivity or any other physical parameter that may indicate one ormore characteristics of a well. The data once collected may betransmitted, through data transmission means (e.g., copper cables, fiberoptics or any other available data transmission means) 132 to aprocessing and control system 110.

The data processing and control system comprises one or more dataprocessing devices, including digital computers, data visualizationmachines and power control units. The data processing and control systemalso allows a user to monitor operations and provide manual input foradjustment. The data processing and control system may execute one ormore computer programs for analyzing data and one or more computerprograms to provide optimization solutions to maximize the system'sefficiency.

The output 122 of the data processing and control system 110 may beutilized to drive the wave radiator 120, by providing for example,instructions to the wave radiator 120, which instructions will be usedby the wave radiator 120 to vary the power output to the geologicalformation 150 in order to achieve the best results in terms ofproductivity. The data processing and control unit 110 may on the otherhand control the power directly fed into the wave radiator 120 in orderto control the amount of power delivered to the reservoir.

The data processing and control system 110 may also feed data back tothe sensing and monitoring system (e.g., 134) in order to better controlthe data collection process.

The invention provides using a system as described above for radiating awell and the formation in combination with one or more applications ofexisting enhanced oil recovery (EOR) treatments. Application of elasticwaves to the well bottom and/or formation provides a synergistic effect,whereby the effects of a treatment using one or more existing EORtreatments is enhanced by the pressure waves provided by the system ofthe invention.

Existing EOR treatments typically rely on the injection of fluids (e.g.,162) into the well. The consistency of the fluids and the amount ofpressure under which the fluid is applied are selected according to thetype of results to be achieved. For example, hydraulic fracturingtreatment (also known in the art of oil recovery as fracking) relies onthe injection of water at a high pressure in order to create newfissures in the rock formation and/or augment existing ones. The highpressure mechanically causes fissures to appear in the rock formation.In addition, the water is loaded with solid particles (e.g., sandgrains, pebbles etc., also known in the art of oil recovery asproppants) that penetrate the fissures and cause the cracks to remainopen once the pressure from the water is removed.

Other EOR treatments rely on loading the fluids with a mixture of acidand/or chemicals. The goal of such substances is many folds: acid maydissolve mineral deposits, organic compounds may dissolve oil and/oroily residues, surfactant may be used to protect equipment from thecaustic environment in the presence of chemicals and/or acids.

Block 162 represents the application of one or more fluids In order toopen new passage ways (e.g., new cracks) or clear existing ones.Existing EOR treatments rely on high pressure to push a fluid, such aswater into, the formation. The fluids may also contain gas (e.g., CO2,H2S, air or any other available gas in any combination of concentrationin a mixture), and/or a liquid and/or steam.

Each existing EOR treatment requires a specific system for application.Since the amount of pressure used, the fluid and the consistency of thefluid can be significantly different, a system (e.g., 160) comprisespumping systems, monitoring systems, fluid supply, fluid storage andspent fluid recovery system. In the industry of oil and/or gas recovery,entire companies may become specialized in only one or a few EORtreatments, given the complexity of each one of the treatments and thevarious logistics involved in each application.

Block 166 represents the fluid supply to the EOR treatment system.Typically, a fluid may be prepared on-site (or transported from a remotelocation), and is provided to the application system (e.g., 160).Treatment typically involves equipment for recovering (and disposing of)spend fluid (e.g., block 168).

EOR treatments reactivate the flowing of the natural resource after ablockage by sediment deposit, decantation, mineralization, paraffinand/or any other substance that may contribute to clogging the passageways. Each one of the physical phenomena involved in improving wellproductivity can be aided by the application of elastic waves. Highfrequency elastic waves cause materials to shake at a very small scale,thus providing a mixing effect which augments the reactivity ofchemicals and/acids with their substrates. Low-frequency vibrationscause fissures to open wider under the effect of pressure waves andallow the proppants to penetrate deeper into the fissures, thus causingthe passage ways to open wider, and letting more natural resource fluidsflow through more easily.

Deployment Environment and Context of Operations

FIG. 2A shows a schematic representation of a typical well forextracting oil and/or gas, aiming at presenting the context in which anembodiment of the invention is utilized. Well 220, for extracting fluidsfrom a geological formation, comprises a hole drilled in the ground. Theinner side of the hole then lined with a cement layer 225 and a casing228 that houses and supports a production tube string 230 coaxiallyinstalled in its interior. Perforations 240, in the well lining, providea path or trajectory that allow fluids produced in the reservoir 210 toflow from the reservoir 210 toward the collection area of the well.

Typically, there are numerous perforations (e.g., 240) that extendradially from the lined or coated well. Perforations are generallyuniformly separated in the lining, and pass to the outside of the liningthrough the formation. In an ideal case, perforations are only locatedwithin the formation, and their number depends on the formationthickness. It is rather common to have nine (9), and up to twelve (12)perforations per depth meter of formation. Other perforations extendlongitudinally, and yet other perforations may extend radially from a0°-azimuth, while additional perforations, located every 90° may definefour sets of perforations around azimuth. Formation fluids pass throughthese perforations and pass into the lined (or coated) well.

Preferably, the oil well is plugged by a sealing mechanism, such as ashutter element (e.g., 232), and/or with a bridge-type plug, locatedbelow the level of perforations (e.g., 234). The shutter element 232 maybe connected to a production tube, and defines a compartment 205. Theproduction fluid, coming from the formation or reservoir, enters thecompartment and fills the compartment until it reaches a fluid level.Accumulated oil, for example, flows from the formation and can beaccompanied by variable quantities of natural gas. Hence, the linedcompartment 205 may contain oil, some water, natural gas, and solidresidues, with normally, sand settling at the bottom of the compartment.

A tool 100 for stimulating the well in accordance with embodiments ofthe invention, may be lowered into the well to reach the level of theformation. The tool may be connected to the ground surface through anattachment means 250 or simply attached to the extremity of the tube 230using an adapter (see below), or even between two portions of the tube230 (e.g. when the well has more than one extraction zone, more than onetool may be lowered). Thus, a tool 100 may be lowered momentarily into awell for well treatment, or alternatively by attaching the tool betweentwo portions of the tube 230 or to the end of the tube 230, the tool maybe operated even as the production continues from the well. Theattachment means comprises a set of cables for providing the mechanicalstrength for holding the weight of tool 100. The attachment means mayalso comprise power cables for transmitting electrical energy to thetool, and communication cables such as copper wires and/or fiber opticsfor providing a means of transmitting data between control computers onthe ground and the tool.

FIG. 2B shows a schematic representation of a typical well forextracting oil and/or gas undergoing a dual treatment with elastic wavesand one or more EOR treatments in accordance with an embodiment of theinvention. Typically, existing EOR treatments involve installing a tube240 to supply the well bottom with a fluid 242, a tube 244 for removingspent fluid, and when high pressure is used, installing one or moreplugs (e.g., 233 and 234) to isolate a segment of the well bore to betreated with high pressure. Ground equipment (e.g., storage tanks,mobile tanks, pumps and necessary equipments) are used to supply thefluid 242 and pressure 248 if necessary. other ground equipments aretypically necessary (e.g., by applying negative pressure 249) to removespent fluids.

Area 260 represents a magnification of a small area of the rockformation, showing the details of cracks (e.g., 262) in the formationand how scaling (e.g., 264) due, for example, to mineral depositingleads to the narrowing of an opening 266. Over time, the layer 264 ofdeposits grows, thus narrowing the fissures and closing the passage waysthough which natural fluids flow. In the latter case, acidizingtreatment is adequate to dissolve the mineral deposits and increase thediameter of the orifices.

Area 270 represents a magnification of small area showing the details ofcracks (e.g., 272) in a rock formation where hydraulic fracturingtreatment is schematically represented. Cracks in the formation areflared under the pressure of water from the EOR treatment. The proppants274 travel through the cracks under pressure and settle therein, thuspreventing the cracks from closing after the pressure has been removed.

The invention provides a method and system for applying low-frequencyand high-frequency elastic waves in combination with the application ofone or more EOR treatments. For example, the high-frequency 280 elasticwaves provide the capability of energetically mixing the chemicals/acidswith the materials of the rock and/or the sediments blocking the pores.The application of such high-frequency vibrations has a synergisticeffect promoting the effects of the application of any treatment thatinvolves a reaction (chemical or otherwise) at the microscopic level.

Low-frequency elastic waves 285 have a wave length in the macroscopicrange, and are capable of displacing solids as well as fluids.Furthermore, because of their large wave-length, low frequency elasticwaves are able to travel over a long distance. Due to the latterproperties, application of low-frequency elastic waves, in accordancewith the invention, may promote a more efficient settling of proppant inthe fissures than would have otherwise be expected with hydraulicfracturing treatment alone, for example.

General Description of an Elastic Waves Generating Device

FIG. 3 is a block diagram representing components of a well stimulationdevice in accordance with embodiments of the invention. Device 100comprises one or more elastic waves radiating means 310. The elasticwaves radiating means may be any device capable of generating vibrationpower, which is transmitted to the geologic formation in order tofacilitate the movement of the natural resource toward the well forcollection. Device 100, in accordance with an embodiment of theinvention, comprises one or more chambers (e.g., 320) for hosting thewave radiators, power supply units, sensing equipment and any othercomponent of the device.

Chamber 320 provides an important role for implementing embodiments ofthe invention. Chamber 320 provides an environment in which temperature,pressure and other physical parameters may be controlled in order toprovide an adequate environment for an efficient functioning of device100. For example, chamber 320 may be filled with a liquid that acts as aheat sink in order to protect equipment from the heat generated duringoperation. Chamber 320 may be designed with specific resonanceproperties to optimize the efficiency of the vibrations. Chamber 320 maybe sealed to allow for high pressure inside the chamber in order tocounteract the cavitation phenomena that may accompany application ofsound waves to the liquid filling the chamber.

Device 100 comprises a power supply unit 330. The power supply unitcomprises electronic circuitry, such as one or more circuit boards forconverting power (Alternating and/or direct power) into one or moreregimes of power as required by any specific type of wave radiationmeans comprised in the device 100. Power supply unit 330 also comprisesenergy storing components (e.g., one or more capacitors) capable ofstoring electric power and delivering the power, either automaticallyand/or under the control of an electronic signal.

Device 100 comprises a sensing system 340 which includes one or moresensors capable of detecting physical parameters in the well andcollecting data that can be transmitted to and processed by dataprocessing centers. The sensors may be hosted within a chamber that maybe part of other chambers of device 100. Alternatively, the sensors maybe hosted in a chamber that is connected with other chambers through anopening 250. The latter may be useful for allowing the liquid acting asa heat sink to freely flow and protect the sensors.

Device 100 may be constructed partly or in its entirely fromcorrosion-resistant materials. In accordance with embodiments of theinvention, device 100 is designed to resist the harsh chemicalenvironment attacks present in the operation zone. For example, device100 may be constructed using a steel cylinder having a wall thicknessadequate for heat dissipation and vibration transmission adequate fordesired sound and temperature properties for a specific applicationenvironment, while the surfaces are coated with a corrosion-resistantcompound in order to protect the device and its components from chemicalattacks.

Details of an Elastic-Wave Generating Device

FIG. 4 represents a longitudinal section view through a device forstimulating wells in accordance with an embodiment of the invention. Thedevice 400 is one example of an implementation of the device and systemas provided by the invention. Device 400 comprises a chamber 460. Thechamber 460 preferably having a cylindrical shape, possessesanticorrosive properties and provides a heatsink. Device 400 may belowered inside the well using a cable 410. The cable 410 comprises oneor more electrical conductors, and is strong enough to support its ownweight and the weight of device 400.

The chamber 460 may be made of a corrosion-resistant material, elasticenough for resisting mechanical vibrations. Chamber 460 comprises two(2) sections: a protective chamber 462 and a controlled-environmentchamber 464. The protective chamber 462 comprises an upper cover 420, aseparator 450, and a chamber wall 440. The controlled-environmentchamber 464 houses measurement and control sensors 435, and is resistantto mechanical waves produced by the wave radiator.

Device 400 comprises a wave radiator 430. The wave radiator may have anyform, and may be fabricated using materials that conducive to producingvibration waves such one or more magnetostrictive transducers. Theinvention allows for implementing transducer of several types and shapesdepending of the target application, which in turn depends on theconditions in each formation.

In the example of FIG. 4, the wave radiator 430 is powered by wires 410,adequately connected through the upper seal 420. The radiator may be inother instances powered by a local power supply unit comprised withindevice 400.

The upper cover 420 and the separator 450 may be made ofcorrosion-resistant materials, and are specially designed to support thehigh pressure present in perforated zone of the well 210. The controlleddeformation chamber is flooded with an insulator heat-sink liquid 445.This heat-sink liquid 445 surrounds the wave radiator 430. Said liquid445 has a cooling function, allowing dissipation of heat generated bythe acoustic wave radiator, and efficiently transferring said heat tothe surroundings. The corrosion-resistant heat-sink chamber 460 ispressurized to prevent cavitation phenomena that may be generatedthrough the application of sound waves. The value of internal pressurein the corrosion-resistant heat-sink chamber is adjusted depending onindividual characteristics of formation and of the power level used.

The controlled environment chamber 464 may be fabricated of a materialresistant to mechanical waves generated by the wave radiators 430.Inside the controlled environment chamber are measurement and controlsensors 435. The main objective of this controlled environment chamberis to protect said sensors from corrosion and degradation due tohydrocarbons present in the formation, and from the waves produced bythe one or more wave radiators 430.

Chamber 460 may be compartmentalized into two or more sub-chambers(e.g., 462 and 464) and the sub-chambers may be interconnected to allowfree passage of the heat-sink liquid.

The purpose of measurement and control sensors 435 is to acquireinformation about temperature in the internal space of the chambers,reservoir pressure, and structural integrity of the chamber wall 440.This information is used to affect an automatic and/or manual control ofthe acoustic device 400, to optimize hydrocarbon extraction from theformation, or to detect operation failures of the device.

In embodiments of the invention, magnetostrictive transducers may beused. Such transducers need to be coiled by a special kind of wire: Thewire must resist high electric currents (which in some cases may riseover 200 Amperes), and high temperatures (over 200° C.) and corrosion.Teflon insulated wires could be used to surpass the corrosion and hightemperature issues. To resist high electric currents the cable's gaugeshould be determined to fit the specific requirements of the application(e.g. to resist currents up to 41 Amperes, a AWG #12 cable is advised).

In other embodiments, where the magnetostrictive transducers areprotected from corrosion and from high temperatures, the cable'sinsulation could be modified in order to diminish the volume occupied bythe coil, e.g., enameled wire could be used instead of Teflon.

FIG. 5 is a block diagram representing components of a high-powergenerator for powering one or more magnetostrictive transducers inaccordance with one embodiment of the invention. An implementation ofthe invention may use one or more magnetostrictive transducers asultrasonic radiators.

Block 510 represents a control unit, that provide a user and/or systemto select the power level and regime (e.g., operating frequencies) todrive the magnetostrictive devices. Block 520 represents a power supplyunit that receives power 530 input (e.g., from a tri-phasic power linehaving three lines of 380 Volts). Block 540 represents a component forgenerating power for an ultrasonic power generator. Its output (e.g.,550) may for example be a 520 Volts at 23,000 KHz. Block 560 representthe power generator for a magnetizing current. The output current (e.g.570) may be for example a 10 Amperes current.

The power generator, as represented in FIG. 5, may produce high powerultrasonic signals that travel trough a submersible cable to theradiator placed in the wellbottom, wellbore region or perforated zone ofthe well.

Attachment Cables and Power Supply Lines

FIGS. 6A and 6B show a cross section view and a perspective sectionview, respectively, of a submersible cable as used in one embodiment ofthe invention. Embodiments of the invention may use a submersible cableto carry high power signals produced by a generator to one or moremagnetostrictive transducers placed inside the well, e.g., when thegenerator is installed on the ground surface. Such submersible cableshould have minimal energy losses. The submersible cables of FIGS. 6Aand 6B comprise a plurality of conducting cables, each of which having aconductor core (e.g., 620 and 622), a dielectric (e.g., 630 and 632) anda lead (e.g., 610 and 612). The conducting cables may be surrounded, forstrength, by an iron cover (e.g., 640 and 642).

Magnetostrictive Device Manufacturing Process

Acoustic waves may be generated by means of a transducer (e.g., 310).This transducer may utilize a piezoelectric or magnetostrictive, or anyother means capable of generating elastic waves. In one embodiment ofthe invention, the device 400 utilizes a magnetostrictive transducer. Itis preferred that the material of the transducer was not onlymagnetostrictive, but also soft magnetic. A magnetostrictive material isone that undergoes physical change in shape and size when subjected to amagnetic field. On the other hand, soft magnetic materials becomemagnetic in the presence of an electric field, but retain little or nomagnetism after the field is removed. Many well known alloys have thesecharacteristics, being suitable for this application, for examplenickel-iron or cobalt-iron alloys. An iron-cobalt-vanadium alloy wasused in embodiments of the invention, such alloys are available forexample under the commercial names of Permendur and Supermendur. Theinvention may be practiced, however, with any alloys that presents thecharacteristics described above.

To avoid losses due to eddy currents, it is preferred to form eachtransducer with a stack of plates of the magnetostrictive material witha layer of a dielectric material in between each plate. The plates needto be thin enough to avoid eddy currents but sufficiently thick to havea magnetostrictive effect that would successfully produce the requiredacoustic waves. According to the invention, plates may have a thicknessof between 0.1 mm and 4 mm. In one embodiment of the invention, theplates have a thickness of 0.15 mm thickness.

The magnetostrictive principle works with a plurality of geometries. Thedevice, according to one embodiment of the invention, utilizes thelength of the plates as determined to be half of the wavelength of themechanical waves in said magnetostrictive material. The latter maximizesthe elastic wave generation.

FIG. 7A is a flowchart diagram of method steps involved in fabricatingelastic waves generator using magnetostrictive material in accordancewith an embodiment of the invention. At step 710, the material isstamped into plates. For optimal magnetic properties, an annealing heattreatment may be required, after the stamping process and beforestacking. At step 720, the plates are heat treated. One of therecommended heat treatment has to be done in a dry hydrogen or argonatmosphere, or in a vacuum atmosphere, to minimize oxide contamination.The entry due point should be dryer than −51° C. and the exit due pointdryer than −40° C. when the inside retort temperature is above 482° C.(See FIG. 7B).

At step 730, a resin is applied to the plates. Then, at step 740, theplates are stacked. Each transducer may have, for example, between 100and 400 plates, and in one embodiment of the invention a transducer mayutilize between 250 and 350 plates. To avoid losses due to undesiredlongitudinal waves, the transducer height (given by the number ofplates) and width should be similar. The dielectric material can be forexample an epoxy resin. In this case, the resin under the trade nameSintepox LE 828 was used. The thickness of the dielectric layer can bebetween 0.01 mm and 0.05 mm, and a 0.025 mm thickness was used in thepresent device. The application of the resin can be done in severalways. For example, the resin may be manually applied using a brush,soaking the plates in the resin, with an aerosol or with any otheravailable means for applying resin.

The stacking of the plates can be done manually or automatically. Afterapplying the resin the plates are stacked applying pressure to eliminateresin excess and control the dielectric layer thickness. At step 750,the plates are dried using an optimal curing temperature according tothe resin data sheet.

FIG. 7B is a plot of the temperature for curing resin versus time ofcuring in accordance with embodiments of the invention. Curve 760generally shows that curing is applied between 1 and 13 hours with atemperature of 0 to around 900° C.

During operation, a wave generator in accordance to the inventionproduces mechanical vibrations. The mechanical vibrations promoteformation of shearing vibration in an extraction zone, due to phasedisplacement of mechanical vibrations produced along one axis of thewell, thus achieving alternating tension and pressure forces due tosuperposition of longitudinal shear waves, and so stimulating the masstransfer processes within the well.

Elastic Waves Propagation

FIG. 8 shows a set of plots that represent vibrational energy transferalong the longitudinal and radial axes between a device implementing theinvention and the surrounding area in the operation zone. Theoscillating velocity vector VR1 (28) from longitudinal vibrations,propagated within the chamber of the device (e.g., 460) is directedalong the axis of said chamber. Simultaneously, the amplitudedistribution of vibratory displacements ξ^(R) _(ml)(30) of longitudinalvibrations is also propagated along the chamber. In place of the above,and as a result of Poisson effect, radial vibrations are generated inthe chamber, which has a characteristic distance, and an amplitude ofdisplacement ξ^(R) _(nV) (31).

Radial vibrations through the radiant surface (32) of either the elasticwave radiator (32) or the chamber are transmitted to the inside of thereservoir (33) surrounding the well. Velocity vector V^(Z) ₁ (34) oflongitudinal vibrations is propagated to the reservoir (33) surroundingthe well in a direction perpendicular to the longitudinal axis of thechamber. Diagram 35 shows the radial distribution characteristic ofdisplacement amplitudes ξ^(Z) _(ml)(39) of radial vibrations propagatedto the reservoir (33) surrounding the well; they are radiated frompoints of the chamber that may be located at a distance equal to λ/2, λbeing the wavelength of longitudinal waves in the material of resonancechamber.

Phase displacement of radial vibrations propagating in the mediumgenerates shearing vibrations in a perforated region of the well, whoseoscillating velocity vector V_(ZS) (36) is directed along the axis ofthe chamber. Diagram 37 shows the characteristic distribution ofdisplacement amplitudes of shearing vibrations ξ^(Z) _(mS).

As a result of the superposition of longitudinal and shearing waves, anacoustic flow (jet streaming 38) is produced in the perforated region ofthe well (e.g., 210), improving the desired effect of viscosityreduction and mass transfer.

Layout Example of a Plurality of Elastic Wave Generators within a Device

FIG. 9 illustrates the geometry of a device implementing the inventionwhere the layout of transducers in relation with wave propagationproperties is used to optimize the amount of vibration energytransferred to the surrounding operation zone. FIG. 9 illustrates animplementation where one or more transducers (e.g. 910 and 912) aremounted within the chamber of the device, thus allowing the transducersto be submerged in the heat-dissipating liquid. In the latterconfiguration, the radiation of elastic waves is carried out by the wallof the chamber 902. Therefore, the geometry of the each of the componentof the device and their respective specific resonance frequencies aretaken into account when implementing the invention. For example, whilewaves are propagating through the device from one or more transducers,oscillating waves of similar frequencies cancel each other in someregions (e.g. nodes 920, 921 and 822), and superimpose in other regions(e.g., anti-nodes 930 and 931). The distance of the transducers (e.g.,910 and 912) with respect to each other (e.g., 940) and with respect tothe wall of the chamber (e.g. 942) and with respect to the wave-lengthof the elastic wave (e.g. 944) may be critical to the resonance to thedevice implementing the invention. Therefore, the invention provides amethod for laying out the one or more transducers with the device inorder to optimally apply the vibration energy to the operation zone.

For example, a radiant surface 902 having a tubular geometric shape,with an external diameter D_(O), and geometric dimensions of radiantsurface, length “L” and wall thickness “λ” may be determined by workingconditions under resonance parameters of radial and longitudinalvibrations, at natural resonance frequency of the wave radiator. Toimplement the principle above indicated, regarding formation of asuperposition of longitudinal- and shear waves in the perforated regionof the well, the length “L” of the chamber should be at least half ofthe longitudinal wavelength λ of the acoustic wave inside the materialof the radiant surface; that is, L≧λ/2, e.g., in an oil well with achamber made of stainless steel, the sound velocity in such stainlesssteel at 100 atm pressure is approximately 6000 m/s, and the radiatoroperating at a 25 KHz frequency, the wavelength is 24 cm, thus thelength ‘L’ must be at least 12 cm long.

Resonance Chamber and Guidelines for Construction and Layout of ElasticWaves Generators

FIG. 10 illustrates the interaction between the transducer and the wallof the chamber when geometry is adequately configured to utilize theresonance properties of the device implementing the invention. A wavegenerating source 1010 may be situated within a quarter if the wavelength 1030 (λ/4) from the chamber wall 1020. An incident wave 1040emitted by the wave generating source 1010 causes the wall 1020 tovibrate within a given deformation distance 1022. The vibration of thewall, in turn, becomes a powerful source of a sound wave 1050. Inaddition, the incident wave cause a reflected acoustic wave 1042. Thereflected acoustic waves, although will be attenuated as they travel inthe liquid filling the chamber, contribute to the amplification of thevibrations in accordance with the resonance properties of the device.The radiation of power as elastic waves to the extraction zone in thegeologic formation is thus carried without bringing the wave generatorin contact with the geologic formation. The acoustic waves generated bythe wave generator are transmitted through the liquid to the chamberwall which has a geometry that is critical to transmitting (andeventually) amplifying the acoustic waves. The adequate geometry inaccordance with embodiments of the invention comprises a chamber whoselength is a multiple of the wave length of the vibration.

Alternative Layouts for Vibration Transmission

FIG. 11A illustrates examples of geometries for the layout of aplurality of acoustic wave sources hosted within one or more devicesimplementing the invention. The devices represented in 1110 and 1120have respective device length of 1112 and 1122, which attribute to theirrespective device a resonance frequency. In device 1110, the distanceseparating a pair of acoustic sources may be a multiple of the wavelength, whereas in device 1120, the distance separating a pair of liquidacoustic sources may be half the wave length. In either case, theseembodiments of the invention result in using the resonance properties ofthe device to amplify and transfer the wave's energy to its surrounding.

FIG. 11B illustrates geometries of various dispositions of an acousticwave source with regard to the wall of the chamber in accordance withone or more embodiments of the invention. An acoustic wave source (e.g.1130) may be mounted in contact with the wall 1135. Wave energy is thentransmitted to the wall 1135 both through direct contact and through theheat dissipating liquid 1131.

An acoustic wave generator, such as 1140, may be mounted so as notdirectly touch the wall 1145. The acoustic wave energy is thentransmitted to the wall 1145 through the liquid 1141. In an otherinstance, an acoustic wave generator, such as 1150 may be connected tothe wall 1155 through a wave guide 1158. The wave energy, in the lattercase, is transmitted to the wall 1155 through both the liquid 1151 andthe wave guide 1158.

Several dispositions of one or more wave radiators may be implemented.For example:

-   -   in-phase wave radiators placed every integer multiples of the        wavelength (nλ), in direct contact with the chamber wall,    -   in-phase wave radiators placed every nλ, without direct contact        with the chamber wall,    -   in-phase wave radiators placed every nλ, with a waveguide which        connects said radiators with the chamber wall,    -   180° out-of-phase wave radiators placed every n λ+λ/2, in direct        contact with the chamber wall,    -   180° out-of-phase wave radiators placed every n λ+λ/2, without        direct contact with the chamber wall,    -   180° out-of-phase wave radiators placed every n λ+λ/2, with a        waveguide which connects said radiators with the chamber wall.

FIG. 12A and FIG. 12B represent a longitudinal and transversal sectionviews, respectively, of a device implementing the invention where one ormore acoustic waves generators are in direct contact with the wall ofthe radiating chamber.

In the embodiment shown in FIGS. 12A and 12B, the device implementingthe invention 1200 comprises one or more acoustic wave radiators (e.g.,1220, 1224 and 1230) the radiant surface of which is in direct contactwith the fluids of the formation. The acoustic radiators e.g., 1220,1224 and 1230) emerge through orifices 1240 in the chamber wall 1210.The chamber maintains its capacities to protect the inner components ofthe system and provide a heat dissipating capacity, through the use ofthe heat dissipating liquid 1250, because the gap between the waveradiator(s) and the orifices may be completely sealed with a seal 1245.This disposition is primarily used to avoid major losses due to wavereflection and/or attenuation of the mechanical waves produced by thewave radiators (e.g., 1220, 1224 and 1230).

Alternative Mounting Layout of Device in the Well

FIG. 13 shows a longitudinal section view of a device implementing theinvention where the diameter of the device exceeds that of the tubing ina well, and the means to attach the device to the tubing. Device 1300has a diameter 1302 larger than the diameter 1312 of the tubing 1310,but smaller than that of the casing or external tube. In the latterparticular case, the tubing 1310 must be completely withdrawn, and theelastic wave device implementing the invention must be connected inbetween two sections of the tubing 1320 or to the end of the tubing1320. The cable 1330, in the latter case, must run along outside the‘tubing’ 1310 and must be introduced into the device through a hole(e.g., 1332) in the adapter 1320.

FIG. 14 a longitudinal section view illustrating several layers thatallow a tubing in accordance with an embodiment of the invention toenhance the heat transfer rate to the crude in the reservoir in order toreduce viscosity of crude oil. To maintain the higher temperature of thecrude oil and therefore reduce its viscosity, a heating device 1420 maybe installed alongside the tubing 1440, which heats the tubing acrossthe whole length of the well. E.g., the heating device 1420 may beinstalled in the space between the tubing and the casing 1410, being thetubing thermally isolated 1430 from the surrounding environment; and itcould be powered by a generator placed in the well surface.

Methods for Applying Elastic Waves Stimulation

FIG. 15 is a flowchart diagram representing the overall steps comprisedin deploying a system embodying the invention, applying one or morepreliminary treatment, and permanently operating the system. Step 1510represents several stages in the planing of the deployment, adapting thesystem to the type of the intended treatment, connecting the variousparts of the system, and testing the functioning of the system. Step1510 may be viewed as a pre-installation phase, since the system may bemoved several times, and operation may be alternately started andstopped in order to determine an operation location, take measurementsand carry out any necessary task required for the well functioning ofthe system at later stages.

Following the pre-installation, one or more treatments may be carrieddepending on the type of well, the resource to be extracted and thestate of the resource to be extracted. For example, depending on thecontent in gas of an oil well, or the viscosity of the crude oil in thewell, a determination may be made to treat the well in one or many waysbefore the system is permanently installed and operated.

For example steps 1520, 1530 and 1540, respectively represent stages ofwell cleaning, heat treatment of the well and/or cleaning a well underpressure. Once the well has undergone one or more treatments (e.g.,steps 1520, 1530 and 1540), the tool can be permanently installed andoperated in-situ.

FIG. 16 is a flowchart diagram showing steps involved in deploying adevice implementing the invention. At step 1605, a device implementingthe invention is connected to the power supply. A series of electricalconnections made on the surface that are necessary for the properoperation of the system. For example, the connection may be made througha tri-phasic power line (see above) to the ultrasonic generator,electric connection between the ultrasonic generator and the geophysicalcable and electrical checking of the connections through continuitytests.

At step 1610, the device geophysical cable is connected. Connection ismade between the acoustic tool and the geophysical cable. Step 1610involves connecting the positioned tool in the wellbottom, wellbore orperforated zone of the well, to a geophysical cable of a proper length.In addition, step 1610 involves checking the electrical connectionsthrough continuity tests.

At step 1615, the device implementing the invention is joined to thetubing. The latter step involves connecting the device to the tubing,using for example, a standard couple in the oil industry.

At step 1620, a device implementing the invention is deployed. Thelatter step involves installing a tuning string with the acoustic toolattached to its end through a rig truck and a temporal wellhead. Thelatter step also comprises checking the electrical connections throughcontinuity test.

FIG. 17 is a flowchart diagram representing steps of cleaning a wellbefore permanent operation in accordance with one embodiment of theinvention. At step 1725, a swabbing operation of an oil well, forexample, may be carried out to extract the liquids inside the wellthrough a rig truck, in order to attain a certain objective liquid levelinside the oil well.

At step 1730, pressure and temperature are surveyed, among otherphysical variables (e.g. viscosity). The latter step involves measuringtemperature and pressure profiles before the acoustic well stimulation.Further temperature and pressure measurements are conducted after theacoustic stimulation, and the profiles are compared in order todetermine the changes that are the result of the acoustic treatment.

At step 1735, a device implementing the invention is temporarilypositioned at a point of interest (e.g., wellbottom, wellbore orperforated zone of the well) in order to conduct well cleaning at thatparticular point of interest.

At step 1740, the device is started, which involves switching on theultrasonic generator, setting up the working parameters (frequency,current and power). The latter step further involves checking thecorrect functioning of the system through current and voltagemeasurements at the output of the generator.

At step 1745, the point of interest previously selected is cleaned bytemporarily operating the acoustic device in a specific depth, and itssubsequent repositioning to another point of interest.

At step 1750, a measurement of fluid level is carried out of the liquidin the wellbottom, wellbore and/or the perforated, by means of adequatetools (e.g. EchoMeter). The latter measurement may be crucial in orderto maintain the pressure in the wellbottom so that an efficient acousticpower transmission is achieved.

FIG. 18 is a flowchart diagram representing steps comprised in theprocess of cleaning a well in accordance with an embodiment of theinvention. At step 1820, a well is flooded. In the latter step,completely flooding the well to helps the acoustic power transmission tothe operating zone (wellbottom, wellbore and perforated zone of thewell). At step 1830, the well is sealed. Sealing the well by means of astandard retention valve prevents high pressure gas from escaping. Atstep 1840, a device implementing the invention is positioned in thewell. The device is temporarily positioned at a point of interest (e.g.wellbottom, wellbore or perforated zone of the well). At step 1850, thedevice is started. At step 1850, the one or more ultrasonic generatorsare started, and working parameters (frequency, current and power) aresetup. The latter step comprises checking the correct functioning of thesystem through current and voltage measurements at the output of thegenerator.

At step 1860, the point of interest where the device was positioned iscleaned by temporary action of the acoustic tool at a specific depth,and its subsequent repositioning to another point of interest.

At step 1870, the pressure is released following the cleaning at everydepth in order to stimulate the movement of the obstructive particlesand their natural decantation to the wellbottom.

FIG. 19 is a flowchart diagram representing steps comprised in heattreatment of heavy oil in accordance with one embodiment of theinvention. Oil wells with a high content of paraffin may be treatedusing an in-situ heating system.

At step 1905, a well is flooded (similarly as described above). At step1910, the heating device is installed along the tubing (as described inFIG. 14). At step 1930, the device implementing the invention isinserted in to the well. At step 1940, the device is positioned at apoint of interest (as described above). At step 1950, the heating deviceis started. At step 1960, the one or more acoustic generators comprisedwithin a stimulation device are started. At this stage, the heat causeto lower the viscosity of the oil, and the acoustic waves cause themechanical displacement of the oil and the removal of fines.

At step 1970, the well is cleaned as described above. At step 1980, thelevel of fluid is measured for further adjustment of the treatment timeand parameters.

FIG. 20 is a flowchart diagram representing steps comprised in thepermanent installation of a system embodying the invention. At step2010, a device implementing the invention is positioned at a specificoperating depth for permanent operation.

At step 2020, well landing is carried out. The latter step involvesinstalling and deploying a pumping device. This stage includes theremoval of the temporal wellhead of the well, the disconnection of thegeophysical cable from the generator, the connection of the geophysicalcable to the permanent wellhead of the well. The well is closed andsealed

At step 2030, the permanent regime is started. The latter step involvesacoustically stimulating the well in a permanent regime, which may becarried out concomitantly with oil extraction.

At step 2040, the well and the device are monitored, and one or moreoperating parameters of the acoustic stimulation system (frequency,power and magnetizing current) may be modified to optimize theperformance of the treatment.

Low-Frequency Application Through Modulation of High-Frequency ElasticWaves

During operation, a device for generating acoustic waves in accordancewith embodiments of the invention may be operated using a continuouspower signal, a pulsed signal or any other mode a user may determinedappropriate for any given treatment. For example, control system 110,may deliver power to the wave generator in wide range of power andfrequency, where the level may be determined by the user and/or acontrol system 110.

In embodiments of the invention, the data processing and control system(e.g., 110) may be utilized to drive the wave radiator, by providing forexample, instructions to the wave radiator, which instructions will beused by the wave radiator to vary the power output to the geologicalformation in order to achieve the best results. The data processing andcontrol unit may on the other hand control the power directly fed intothe wave radiator in order to control the amount of power delivered tothe reservoir.

In embodiments of the invention, the wave radiator may be deliveracoustic waves, mechanical waves, electromagnetic waves or any type ofphysical phenomenon capable of delivering vibrational energy to ageological formation.

A control system implementing the invention enables the system toirradiate the geological formation in any operating regime the userdesires, including continued, alternated, pulsed, in amplitudemodulation, frequency modulation, among many other possibilities.

FIG. 21A is a plot of the power as a function of time of a highfrequency continuous signal for driving a wave generator, in accordancewith one embodiment of the invention. Signal 2120 in the example of FIG.21A possesses a sine-shape, however the signal may possess any othersignal shape, such as a square, saw tooth, ramp or any other chosensignal shape. The signal may be applied at a constant amplitude of power2110, either continuously or for any given length of time 2112 at anychosen periodicity. The latter operating regime, i.e. continuous regime,is useful for reducing skin effect in the wellbore, decreasing oil'sviscosity and increasing the formation's permeability, and treatingwells with formation damage.

FIG. 21B is a plot of the power as a function of time of a highfrequency signal for driving a wave generator, where the signal isapplied in an ON/OFF fashion, in accordance with one embodiment of theinvention. In the latter example of power application, signal 2135 maybe applied for any given length of time. Each burst may, for example,have a sine waveform of a constant amplitude 2130, and the burstapplication may be repeated at a constant or variable rate over time2132. In the latter regime of operation, a control system (e.g., 110)may intermittently activate and deactivate a high-frequency power sourcethat drive the acoustic wave generator. A process known as ON/OFFkeying.

FIG. 21C is a graph showing the power level as a function of time of ahigh-frequency signal that is applied in a pulsed mode, in accordancewith an embodiment of the invention. The graph 2145 of FIG. 21C is thepower plot of signal 2135. The power of the wave indicated in scale 2140follows the burst mode as a function of time 2142.

The soil is expected to behave as a natural low-pass filter. At acertain distance, the soil filters the signal, attenuating the highfrequency components, thus acting as a demodulator of an amplitudemodulated (AM) signal.

FIG. 21D is a bode diagram showing the magnitude of the signal and thephase of the signal as a function of frequencies of signals propagatedthrough a geological formation in accordance with applications of theinvention. Curves 2155 and 2165, respectively, show the magnitude and2150 and phase 2160 of signals applied to a geological formation as afunction of the frequency of the signal 2162 at a given distance fromthe source where the acoustic wave was initiated. Plot 2150 shows thatthe power transfer within the geological formation decreases as thefrequency of the vibration increases.

Because of the integration properties of a low pass-filters in general,and of the soil with regard to acoustic waves in the present case, aburst of high-frequency waves results in a low frequency power transferwave.

FIG. 21E is a plot of a low frequency wave 2175 resulting from theapplication of a burst of high-frequency signal. The amplitude of wave2175 on a scale of power as a function of time, in this case, has asquare-like shape that reflects the short period of application of thehigh-frequency signal (see FIG. 21B).

Low-frequency acoustic waves are able to travel longer distances. Thegeneration of low-frequency signals provided by a system embodying theinvention by modulating high-frequency signals allows for a wide rangeof application of low-frequency stimulation along with high-frequencystimulation.

The soil's properties to dampen acoustic vibrations amplitude as thevibration frequency increases may modeled as a low-pass filter having abandwidth of

Bw=[0, f_(c)]

Where “f_(c)” is the soil's cutoff frequency, that may vary depending onthe type of soil being treated.

This low-pass filter can be modeled as follows:

where

$\left| {H(s)} \right. = \frac{K}{\left( {{s^{2}/w^{2}} + {2\xi \; {s/w}} + 1} \right)}$w = 2π f_(c);

and where “H(s)” is the low pass filter transfer function; “K” is thegain of the filter, “s” is the frequency domain variable; “ξ” is adamping ratio of the system; and “f_(c)” is cutoff frequency of thelow-pass filter.

A system embodying the invention is enabled, to exploit the inherentlow-pass filter properties of the soil, coupled with the ability ofembodiments of the invention to generate and modulate high-frequencysignals in order to apply low-frequency acoustic waves to the geologicalformation.

FIG. 22A is a plot of a modulated high frequency signal used to applylow-frequency acoustic vibrations in accordance with an embodiment ofthe invention. Signal 2215 is a high-frequency signal whose amplitude isrepresented on scale 2210 as a function of time 2212. Signal 2215exhibits a high-frequency component whose amplitude has been modulatedat a lower oscillating pattern.

FIG. 22B shows a plot of a signal having a low-frequency that resultsfrom the application of the signal shown in FIG. 22A. Signal 2225represents the power transfer waveform as a function of time 2222 on ascale of power 2220. The wave shape of 2225 results from thelower-frequency modulation of the high-frequency signal.

In a system embodying the invention, amplitude modulation can beachieved when the control system regulates the output power of theultrasonic generator. If the generator gradually periodically decreasesand increases the output power repeatedly the amplitude can thus bemodulated.

FIG. 23 is a plot representing a signal whose frequency is modulated inaccordance with an embodiment of the invention. Signal 2315 is a plot ofpower of the signal on a power scale (e.g., 2310) as a function of time.Using such a frequency modulated signal, coupled with the integrationproperties of low-pass filter provided by the soil, it is possible totransfer both high and low-frequency vibrations into the geologicformation.

Frequency modulation of signals allows for irradiating in a widebandwidth; where the user via the control system sets the stimulationbandwidth. This is very useful when information about the treated wellis unavailable. This stimulation bandwidth could be for example between15 kHz to 25 kHz, in this case the control system would graduallyincrease the ultrasonic generator's frequency from 15 kHz to 25 kHz andthen gradually decrease it to 15 kHz, this process may be repeated whilethe frequency modulation operating regime is enabled.

Pulsed and AM modulated operation, as they radiate high frequency andalso low frequency acoustic waves, they are useful to increase themobility of oils deep into the reservoir, because low frequency acousticwaves travel further than high frequency.

General Method of Combining EOR Treatment with Application of ElasticWaves

As briefly described above, the invention provides a method, apparatusand system for a combined application of elastic waves and one or moreavailable technologies for stimulating production in a well. In the caseof oil/gas recovery, the latter techniques are commonly referred asenhanced oil recovery (EOR) treatments.

FIG. 24 is flowchart diagram showing the overall steps provided by animplementation of the invention for applying a combination of elasticwaves stimulation and another EOR treatment. In a newly constructedwell, or an old well that has been selected for treatment and thepumping kit has been removed, at step 2420, an apparatus comprising oneor more elastic-wave generating devices in accordance with an embodimentof the invention is deployed. The deployment may also take place at alater stage, depending on the type of the EOR with which the elasticwaves treatment is combined.

At step 2430, deployment of the machinery of the selected EOR isundertaken. In the industry of oil production, the latter step mayrequire calling for a team of workers whose expertise is the assessmentof the well, the selection of the necessary logistics to carry out theEOR treatment, the deployment of the machinery, the application of thetreatment, and the cleanup stage at the end of the treatment.

Following the installation of the EOR machinery, the EOR treatment maybe started at step 2440. Starting an EOR treatment involves specificsteps that are selected for the type of EOR treatment. Owing to the datacollecting system of an embodiment of the invention physical parameterssuch as temperature, pressure, acidity and the like, are provided asinput to the EOR technique which may contribute to adjusting sometreatment parameters even before the start of the EOR treatment.

At step 2450, the treatment with the elastic waves may be started. Step2450 may be undertaken before, during or following step 2440. Owing tothe remote control provided by an implementation of the invention,treatment with elastic waves may be optimally adjusted to maximize thesynergistic effect of the vibrational treatment and the EOR treatment.For example, when acidizing a well, the operator of the EOR treatmentmay find it useful to stop the elastic wave treatment during specificstages of the acidizing treatment.

At step 2460, data is collected periodically or in real-time andanalyzed in order to assess the progress of the well stimulation. Basedon the ongoing assessment, a treatment may be continued at step 2440.Otherwise, if the goal of the treatment has been achieved, the treatmentis stopped, the treatment machinery retrieved and the follow upprocedure to clean up the treatment spent fluids may ensue.

One with ordinary skills in the art of EOR treatments is typicallyfamiliar with each type of treatment. Although, these treatments sharesome general steps in the methods of deployment and execution, inpractice the level of skills acquired with each EOR technology increaseswith the amount of experience a person or a team thereof accumulateduring their practice. It is common that a different team of experts iscalled upon for a given treatment. Therefore, the invention

Hydraulic Fracturing Combined with Elastic Waves Application

The invention provides a combination of applying hydraulic fracturingwith elastic waves treatment. Hydraulic fracturing relies on the highpressure exerted on the rock formation (or shale) in order to crack openfissures in the rock or widen the existing ones. Furthermore, the waterused to exert the high pressure is loaded with solid particles (e.g.,sand grains, gravel, pebbles and the like) that are wedged inside thefissures, and remain permanently lodged in the fissures in order to keepthe fissures open after the pressure has been removed.

The pressure waves created by the application of elastic waves, inaccordance with the teachings on the invention, may travel to varyingdistances from the well, depending on the frequency and power of theelastic waves. The effects of applying elastic waves to a well incombination with fracturing treatments, in accordance with embodimentsof the invention, lead to a long-lasting treatment effect, an increaseof oil mobility through new fractures, increased mobility of proppantparticles through cracks in order to keep openings wider and, hence,lasting long for fluid flow.

FIG. 25 is a flowchart diagram representing steps involved in atreatment of a well using a combination of hydraulic fracturing andelastic wave treatment in accordance with an embodiment of theinvention. At step 2510, one or more elastic wave apparatuses embodyingthe invention are deployed in a newly built well, or a depleted wellthat has been selected for treatment.

At step 2520, the machinery for applying hydraulic treatment isdeployed. The latter involves setting up a water supply source, loweringthe tubes into the well, installing plugs to isolate a given portion ofthe well to be treated with high pressure. At step 2530, water is pumpedinto the well and the pressure is raised to levels sufficient to causefissures to open inside the rock formation (or shale).

At step 2540, proppant (e.g., sand and/or any other solid particles usedto lodge inside the fissures) is added to the water. The latter mixtureis blended at step 2550. Then at step 2560, the mixture is pumped intothe downhole.

Following the treatment with the combination of hydraulic fracturing andelastic waves application, the treatment's spent fluids are recoveredand the well is cleaned in preparation for production.

Gas Injection Combined with Elastic Waves Application

Within a reservoir, of oil/gas for example, the natural resource maytravel over time from one area to another area of the reservoir, and/ordiminish in all areas or in some areas faster than others. The latter isdue to several factors, among which that extraction of the resource fromthe reservoir reduces the overall pressure to a point where some wellsbecome insufficiently productive. In other instances the movement offluids such oil and/or underground water causes the natural resource toshift. Movement of fluids as well as seismic type movement, land slideand the like may be responsible for such natural resource movement.

Enhanced Oil Recovery treatment tackle this issue by selecting somewells (e.g., depleted or non-producing wells) to inject a fluid underpressure that results in exerting pressure within the reservoir to pushthe natural resource toward the other producing wells in a productionfield. The injected fluid may be water and/or gas.

In a typical oil field, the fluids pumped out of wells typicallycontain, in addition to crude oil and natural gas, water and other gasessuch as carbon dioxide (CO₂) and hydrogen sulfide (H₂S). Crude oil andnatural gas are separated from the mixture and recovered. But, theresidual water and the gasses typically present a burden to dispose ofthem. These fluids can be re-injected inside the reservoir for permanentdisposal.

When injection of water and/or residual gases is properly planned, anEOR treatment-based injection of fluids can be designed to raise thepressure in a reservoir. To the latter end, a study is conducted todetermine the state of the reservoir. Then some wells (e.g., depletedwells) are chosen for injection of fluids.

The invention teaches a combination of applying fluid injection in somewells with the treatment with elastic waves using an apparatus embodyingthe invention which is deployed in one or more injection wells and/orneighboring producing wells. The effect of a treatment in accordancewith embodiments of the invention, is a synergistic effect whereby themovement of the injected fluid is facilitated by the pressure wavesproduced by the apparatus.

FIG. 26 is a flowchart diagram showing steps involved in gas injectionin combination with elastic waves stimulation in accordance with anembodiment of the invention. At step 2610, a study is conducted and adetermination is made deploy one or more elastic-wave generators in aset of wells, which may included injection wells and production wells.

At step 2620, the gasses and water from at least one well are collectedand separated from the fluids pumped out of at least one well.Typically, the fluids are collected form a plurality of wells.

At step 2630, the gases recovered from the reservoir are treated withamine-bases chemicals. The result of the latter processing is aseparation of CO₂ and H₂S from the recovered fluids. The latterprocessing method is well known in the art of oil and/or gas recoveryand refinery.

At step 2640, the recovered gases are compressed under high pressure(e.g., using a compressor) and stored in high-pressure tanks.Simultaneously, water is also recovered at step 2650, and water vapor isrecovered at step 2660.

At step 2670, the water, water vapor and recovered (then treated) gasesare mixed. Then at step 2680, the mixture is injected underhigh-pressure. In accordance with the teaching of the invention, whilethe mixture is being injected into the well, and/or following theinjection of the mixture, elastic pressure waves may be applied from adevice embodying the invention. The result of the pressure wavesapplication is a faster diffusion of the fluids through the rockformation or shale. Thus, the application of the elastic wavefacilitates the build up of pressure in the rock formation (or shale)with a pressure gradient that is highest at the injection well, thus,decompression results in pushing the fluids toward the producing wells.

The benefit of the combination of treatment of wells with elastic wavesalong with fluid injection treatment include a faster result, whichreduces the time (and cost) of treatment, and increasing the capacity ofthe reservoir to absorb more of the waste gases and water. Furthermore,owing to the physical characteristics of elastic waves

Acidizing Combined with Elastic Waves Application

The inventions provides a combination of using existing acidizingmethods of a well with the application of elastic waves to the well boreand the rock formation (or shale). When a rock formation (e.g.,limestone or dolomite) contains compounds that are soluble in water,small amounts of the soluble compounds tend to be deposited, which overtime tends to narrow the pores and/fissures, and ultimately obstructopenings in the well casing, and passage ways through the fissures inthe rock formation. The application of an acidic water solution, in aprocess called acidizing, may be carried out to reopen previous passageways, or etch new ones. The latter process consists of running a highlyacidic solution in the well in order to dissolve mineral deposits (e.g.,carbonate deposits) and sediments. Pumping the acid into the rock forcesthe creation of channels that connect the formation with the well bore,thus, creating passage ways for oil and gas to flow into the well boreand be collected.

Acidizing creates a very caustic environment, hence, careful planning isrequired to be able to attack the target minerals and etch the rockwhile protecting the treatment equipment and the well structure.

FIG. 27 is a flowchart diagram representing steps involved in acidizinga well in combination with the application of elastic waves to a wellbore in accordance with embodiments of the invention. At step 2720, astudy of the data from the geology of the formation and the history ofthe well is carried out in order to establish the type of acid involvedto be used in the acidizing treatment. Commonly used acids arehydrochloric acid (HCl) and hydrofluoric acid (HF) either alone or incombination. Embodiments of the invention, however, may utilize anyavailable treatment with acid. At step 2730, following the input datafrom surveying the composition of the rock formation and the mineraldeposits, a determination is made as to the concentration of the acid tobe used in the treatment.

At step 2740, an apparatus for generating elastic waves embodying theinvention is deployed in an area selected for treatment. Step 2740 maybe carried out at any stage of the treatment. For example, an apparatusfor generating elastic waves may be deployed after the acid has beenpumped into the well.

At step 2750, the acid solution is injected into the well at a highpressure. At step 2760, elastic-wave stimulation may be carried outduring the application of the acid solution. As described above,pressure waves having various frequencies provide a synergistic effecton the action of the acidizing process at several levels, comprisingimproving the mixing of the acidic solution with the substrates andfacilitating the flow of the solution deeper into the fissures in therock. The benefit of such synergistic effect is a deeper penetration ofthe acid into the surface of rock and a farther travel of the acid intothe formation. The latter benefits may shorten the time of thetreatment, thus, reducing treatment costs, increase the production rateof the well, and prolong the time the well is productive before it needsa treatment again.

Thus an apparatus, method and system for increasing production of anatural resource producing-well, by utilizing an acoustic wavesgenerating device to deliver vibrational energy to the geologicalformation and continuously monitoring and optimizing the stimulationparameters. Furthermore, by combining the acoustic treatment withexisting EOR treatments, the invention provides a method apparatus andsystem for improving the results of any available EOR treatment.

1. A method for stimulating a natural resource producing well, saidmethod comprising the steps of: deploying an apparatus comprising atleast one generator for generating at least one type of elastic wavesinto a wellbore; deploying a system for applying an enhanced recoverytreatment into said wellbore; operating said system for applying saidenhanced recovery treatment; and operating said apparatus for applyingan elastic wave treatment, wherein said applying said elastic wavetreatment creates a synergistic effect on said applying said enhancedrecovery treatment.
 2. The method of claim 1, wherein said step ofdeploying said apparatus further comprising deploying an apparatus forgenerating high-frequency elastic waves.
 3. The method of claim 1,wherein said step of deploying said apparatus further comprisingdeploying an apparatus for generating high-frequency elastic waves andlow frequency elastic-waves.
 4. The method of claim 1, wherein said stepof deploying said system for applying said enhanced recovery treatmentfurther comprising deploying a system for applying hydraulic fracturing.5. The method of claim 4 further comprising: applying a water at ahigh-pressure; adding at least one proppant to said water; blending amixture containing said water with said at least one proppant; andpumping said mixture into said wellbore.
 6. The method of claim 1,wherein said step of deploying said system for applying an enhancedrecovery treatment further comprising deploying a system for applying anacid treatment.
 7. The method of claim 6, further comprising: selectingat least one acid type for applying said acid treatment; determining aconcentration and volume of said at least one acid type for making asolution of acid; pumping a mixture of proppants in said wellbore; andinjection said solution of acid into said wellbore.
 8. A method forapplying pressure to a natural resource in a production reservoir, saidmethod comprising the steps of: deploying an apparatus comprising atleast one generator for generating at least one type of elastic wavesinto a set of wells in a production filed, wherein said set of wellscomprising a subset of production wells and a subset of injection wells;deploying a system for applying a fluid injection treatment into aninjection well of said production field; operating said system forapplying said fluid treatment; and operating said apparatus for applyingan elastic wave treatment, wherein said applying said elastic wavetreatment creates a synergistic effect on said applying said fluidinjection treatment.
 9. The method of claim 8, wherein said step ofdeploying said fluid injection treatment further comprising: recoveringa plurality of fluids from said subset of production wells; separatingat least one injection fluid from said plurality of fluids; treatingsaid at least one injection fluid; compressing said at least oneinjection fluid; and injecting said at least one injection fluid into atleast one well of said subset of injection wells.
 10. The method ofclaim 9, wherein said step of recovering said plurality of fluidsfurther comprises recovering water, carbon dioxide, hydrogen sulfide,and water vapor from said subset of production wells.
 11. The method ofclaim 10 further comprising: separating at least one gas from saidplurality of fluids; and treating said at least one gas with at leastone amine-based chemical compound.
 12. A system for stimulating anatural resource producing well, comprising: means for generating atleast one type of elastic waves into a wellbore; and means for applyingan enhanced recovery treatment to said wellbore.
 13. The system of claim12 further comprises means for generating high-frequency elastic waves.14. The system of claim 12 further comprises means for generatinghigh-frequency elastic waves and low frequency elastic-waves.
 15. Thesystem of claim 12 further comprising means for applying hydraulicfracturing.
 16. The system of claim 15 further comprising: means forapplying water at a high-pressure; means for mixing a mixture comprisingat least one proppant and said water; and means for pumping said mixtureinto said wellbore.
 17. The system of claim 12 further comprising asystem for applying an acid treatment, and further comprising: means forselecting at least one acid type for applying said acid treatment; meansfor determining a concentration and volume of said at least one acidtype for making a solution of acid; and means for pumping a mixture ofproppants in said wellbore.
 18. The system of claim 12 furthercomprising: means for recovering a plurality of fluids from said set ofproduction wells; means for separating at least one injection fluid fromsaid plurality of fluids; means for treating said at least one injectionfluid; means for compressing said at least one injection fluid; andmeans for injecting said at least one injection fluid into at least oneinjection.
 19. The system of claim 18 further comprises means forrecovering carbon dioxide, hydrogen sulfide, water and water vapor. 20.The system of claim 19 further comprises means for chemically treatingsaid at least one injection fluid.